Alfred Russel Wallace 



it most difflcult, but not, I think, impossible, to see how, 

 for instance, a few red feathers appearing on the head of 

 a male bird, and which are at -first transmitted to "both 

 sexes y could come to be transmitted to males alone;' but 

 I have no difficulty in making the whole head red if the 

 few red feathers in the male from the first tended to be 

 sexually transmitted../ I am quite willing to admit that 

 the female may have been modified, either at the same 

 time or subsequently, for protection, by the accumulation 

 of variations limited in their transmission to the female 

 sex. I owe to your writings the consideration of this latter 

 point. But I cannot yet persuade myself that females 

 alone have often been modified for protection. Should you 

 grudge the trouble briefly to tell me whether you believe 

 that the plainer head and less bright colours of $* chaf- 

 finch, the less red on the head and less clean colours of ? 

 goldfinch, the much less red on breast of ? bullfinch, the 

 paler crest of goldencrest wren, etc., have been acquired 

 by them for protection ? I cannot think so ; any more 

 than I can that the considerable differences between $ 

 and (J house -sparrow, or much greater brightness of (J 

 Parus cceruleus (both of which build under cover) than of 

 ? Parus are related to protection. I even misdoubt much 

 whether the less bla€kness of blackbird is for protection. 



Again, can you give me reason for believing that the 

 merest differences between female pheasants, the female 

 Gallus lankivaj the female of black grouse, the pea-hen, 

 female partridge, have all special reference to protection 



1 It is not enough that females should be produced from the males with 

 red feathers, which should be destitute of red feathers ; but these females must 

 have a latent tendency to produce such feathers, otherwise they would cause 

 deterioration in the red head-feathers of their male offspring. Such latent 

 tendency would be shown by their producing the red feathers when old or 

 diseased in their ovaria. 



» The symbols S, ? stand for male and female respectively. 



226 



